Which of the following statements about pulse rate is true?

The statement that the pulse rate varies significantly by age is accurate because heart rates tend to differ among various age groups due to physiological changes as a person matures. For example, infants generally have a higher resting pulse rate compared to adults, with rates decreasing as a person ages into childhood and adulthood. This variation reflects developmental factors and the body's changing metabolic needs over time.

In contrast, the other statements lack validity. Stating that all individuals have the same pulse rate overlooks the wide range of normal resting heart rates that exist due to individual factors such as fitness level, health status, and activity levels. Asserting that only irregular pulses should be counted limits the assessment of a person's heart health; regular, consistent pulses are also critical for understanding overall cardiovascular function. Lastly, pulse rate is indeed influenced by physical activity, as exercise typically raises the heart rate to meet the increased oxygen demand of the body, particularly during strenuous activity.